The present invention relates to a lens accommodation device for a camera that is capable of exchanging photographic lenses.
Some so-called compact cameras, which are to exchange a photographic lens, employ a system wherein a lens group is automatically accommodated when the camera is not used, so as reduce the projecting length of the lens group and to facilitate the portability of the camera.
Such a lens accommodation system is not employed in cameras having interchangeable lenses for several reasons. First, whereas a lens shutter zoom camera employs a single lens, an SLR camera uses a plurality of lenses, some of which may be zoom lenses and some of which may be of a fixed focal length. Furthermore, some type of zoom lenses, such as a vari-focal type zoom lens, have an over-all length that does not change as the focal length of the lens is changed. In addition, even if the over-all length of the lens changes as the focal length of the lens is changed, the amount of the lens length change varies from lens type to lens type. Thus, in order to prevent possible damage to a lens accommodation system, the SLR camera would need to know whether the lens attached to the camera body can be accommodated, and if it can be accommodated, when to terminate the lens retracting operation. Therefore, the techniques used to accommodate a lens on a lens shutter camera are inapplicable to cameras employing interchangeable lenses.